mcginn



April 21, 1964 P. J. MCGINN 3,

CALCULATORS Filed Aug. 14, 1962 3 Sheets-Sheet 1 6'6 F 'fi (63 F1 & 6

INVENTOR. PATRICK JM? GINA TT ORNEY April 21, 1964 P. .1. MCGINN 3,129,880

CALCULATORS Filed Aug. 14, 1962 a Sheets-Sheet 2 April 21, 1964 J MOGINN 3,129,880

CALCULATORS Filed Aug. 14, 1962 4 a Sheets-Sheet 5 weaaxkaaQka' aaaaaa FIG: 15 FIG. 1 5

I k o 5 INVENTOR.

United States Patent M 3,129,880 CALCULATORS Patrick J. McGinn, 40 Pryor St. Bldg. SW., Atlanta 3, Ga. Filed Aug. 114, 1962, Ser. No. 216,777 4 Claims. (Cl. 23574) This invention relates to a calculator and particularly to stylus-operated calculator comprising a small case having stylus-operated wheels thereon with carry-over means from one wheel to the next.

Calculators of the type presented in the present application are sometimes known as pocket calculators because they are small in size and convenient to carry and are manually operated by a stylus. Basically such devices are well known in the art and similar calculators are found in a number of issued US. patents, some of which employ a case on which is located a number of interrelated or interconnected wheels manually operated by gears with a carry-over means to rotate the adjacent and successive gears representing a change over from thousand-s to hundreds to tens and so forth. Since such devices must be small in size, lightweight and also inexpensive because there is a definite limitation both as to the use and demand for such a calculator, it is a common manufacturing problem in all of the prior art devices to construct such a calculator having sufiicient precision to provide dependable operation over long periods of time but at the same time being relatively simple and of few parts requiring little assembly. It is to this aspect namely, simplicity, dependability and inexpensiveness to which the present invention is directed.

A primary object of the present invention is to provide a pocket-type calculator employing a lightweight case or" plastic or the like having the wheels arranged in an inexpensive manner with a dependable carry-over means of simple and inexpensive construction.

A further object of the present invention is found in the particular arrangement of dials in a case which may be manufactured from plastic and the like and having spring means thereon of simple but yet effective construction.

Thinness of construction and lightness in weight are two very important objects and advantages of the present calculator which may be manufactured from lightweight plastic of such overall thin and small construction as to be attached to the outer or inner face of a conventional bank checkbook without adding any unreasonable size or weight to the completed checkbook arrangement.

The lightweight and small construction referred to in the preceding paragraph is an advantage which is made possible through the use of plastic base or the like in which is formed the recesses to receive the dial wheels held in place by a thin cover plate-all of simple and inexpensive construction.

Other and further objects of my invention will become apparent upon reading the following specification taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of the calculator of the present device with a small portion of the back corner removed.

FIG. 2 is a partial, enlarged perspective view of the calculator shown in FIG. 1 with the cover removed exposing the base from gears have been removed.

FIG. 3 is a top plan view of the cover plate shown in FIG. 1 removed from the base.

FIG. 4 is a front elevation view of the front edge of the cover plate shown in FIG. 3.

FIG. 5 is a top-plan view of the spring centering ratchet which fits into the base beneath the cover plate.

FIG. 6 is a front elevation view of the centering ratchet shown in 'FIG. 5

3,129,880 Patented Apr. 21, 1964 FIG. 7 is a top plan view of the top of the case or base of the calculator with the cover removed and without all of the dials and the centering ratchet.

FIG. 8 is a cross-sectional view taken along lines 8-8 in FIG. 7.

FIG. 9 is an elevation view of the case or base shown in FIG. 7.

FIG. 10 is a cross-sectional view taken substantially along lines 10-14 in FIG. 7.

FIG. 11 is a cross-sectional view taken substantially along lines 1111 in FIG. 7.

FIG. 12 is a top plan view of the stylus-operated gear used to enter the number into the calculator shown in FIG. 1.

FIG. 13 is a top plan view of the indicator gear driven by the entry gear on the calculator shown in FIG. 1.

FIG. 14 is an elevation view of the stylus-entry gear shown in FIG. 12.

FIG. 15 is a cross-sectional view taken substantially along lines 1515 in FIG. 12.

FIG. 16 is a cross-sectional view taken along lines 1616 in FIG. 12.

FIG. 17 is an elevation view of the indicator gear shown in FIG. 13.

FIG. 18 is a cross-sectional view taken along lines 18-48 in FIG. 13.

FIG. 19 is a cross-sectional vie-w taken along lines 19 19 in FIG. 13.

The calculator is referred to throughout the specification and designated in FIG. 1 by reference numeral 20 which comprises generally a rectangular base or case 22 of generally solid plastic or other material having various calculator parts or elements beneath a top cover 24 which may be screwed, snapped or Otherwise attached in place and which has a plurality of circular openings or stylus tracks 26 therein around the periphery of which are spaced equally the digits 28 from 0 through 9. Each stylus track 26 defines a circular inner portion 30 connected to the cover 24 and on which are indicated by printing, etching or otherwise a series of equally spaced digits 29 from 0 through 9. The larger outer digits 28 run from 0 counterclockwise to 9 whereas the inner set of digits 29 run from 0 clockwise through 9 for a purpose to be described hereinafter under the heading Operation. Openings in cover 24 provide a plurality of answer windows 34 of small-rectangular construction each having a circular opening 36 adjacent thereto and there being an answer window 34 above and corresponding with each of the stylus tracks 26 and the corresponding indicia and numerals 28. Circular openings 36 are part of the attachment arrangement as will appear hereinafter.

Referring next to FIG. 2, the base or case 22, which may be of solidplastic or similar material, has formed therein (preferably in the molding and forming opera- .tion) circular indentations 40 each defining a track for an answer gear and having a center post 42 formed therein. All of said indentations, except the first one, have a cam 44 formed thereon which is part of the actuating mech anism and the carry-over means as will appear later on.

In the present embodiment there are six stylus open ings or tracks 26 and six corresponding answering windows 34 enabling the calculator to reach the figure 999999 which could represent ($9,999.99) Nine Thousand Nine Hlundred Ninety-nine Dollars and ninety-nine cents. This should be more than sufficient for average use such as on a conventional pocket checkbook.

Still referring to FIG. 2 and also now to the details shown in FIGS. 7 through 19, each of the circular indentations or tracks '40 intersects with adjacent indentations 4t) and also with a second group of circular indentations or tracks or guide means 46. The successive indentations 46 are separated by small shoulders or members 4-8 therebetween. Each indentation 40 has a center post 42. Indentations 40 each receives a respective totaling or answer gear member 5t and each gear 50 has the numbers through 9, designated as 52 thereon, arranged equidistantly about the circumference of a circle having the gear member 50 as the center thereof. Each gear member 50 has a center opening 54 therein and teeth 55.

Each gear 541 is driven by a respective stylus-operated gear 56 in a respective indentation 46 shown in FIG. 12. Each gear -6 has a plurality of gear teeth 58 arranged on the underside thereof extending tangentially therefrom and equidistantly spaced to represent one of the numbers of the numerical indices '0 through 9 and also respective stylus holes '60 adjacent respective teeth 58 and numbers 0 through 9. A center opening 62 is formed in each of the gears 56'.

In the two FIGS, 12 and 13, which are side-by-side in the present drawings, it is apparent that the gear 56 is of solid, disc-like construction on the top with the teeth 58 formed on the bottom thereof adjacent stylus holes 69 and radiating therefrom.

Referring to the elevation views in FIGS. 9, and 1 1, it will appear that the indentations 40' are such that when the respective gears 50 are placed therein with the center hole 54 receiving the center post 42, and the respective gears 56 are seated in the respective indentations 46, the gear teeth 60 on the underside of respective gears 56 mesh with the gear teeth 55' on gear 50 substantially in the same plane, whereby manual rotation of the stylusoperated gears 56, as by insertion of a rod-like stylus or pencil member in the openings 60 and rotation of same about the respective center posts 46, causes rotation of the corresponding and respective gear 50. Both groups of gears 56 and 50 are maintained in proper alignment and position by their respective indentations and track members 40, 4'6 and by means of the thin cover plate 24 on the top thereof.

Proper alignment and centering pressure is maintained on the gears 50, 56 by means of the respective ratchet spring 66, shown in position in the perspective view of FIG. 2 and also shown in FIG. 5, and which spring 66 may be manufactured from a Phosphor bronze spring material with a common base strip 68 that is fitted into a slot 70 formed on the base 22. Each ratchet spring 66 has a bent end portion and angled or elbow portion 72 that protrudes beneath the gear 56 and normally lies between adjacent teeth '58 thereunder, in the manner shown in FIG. 2. This spring 66 and elbow '72 serves the purpose of cansing a ratchet action on each of the respective gears 56 dropping by spring 66 into position between successive gear teeth 6! representing successive digits and at the same time exerting a certain amount of spring pressure on the gear 56 urging it into position against a respective gear 50 and resisting any unwanted displacement.

Each of the gears 5t} is formed or otherwise provided with a single carry-over arm 74 protruding from the gear in the manner clearly shown in both FIGS. 13 and 2. The carry-over arms 74 on each of the gears 50 are arranged so as to be carried across the cam 44 and upon reaching and passing 9 in each respective stylus gear 56 and its associated answer gear 5%, the carry-over arm 74 carries this unit over to the next successive units and the gears 50, 56 return to 0*. Each gear 56 has limited vertical movement on a respective post 42 to allow the carryover arm 74 to ride up on the cam 44 thereby toengage the next respective gear 56. However, normally the carry-over arm 74 is in the wrong plane to contact its own respective gear 56 and only by the cam action at 44 does it rise to contact the next gear 56.

Operation In the operation of the instant calculator, the machine carry the answer windows -34 to show Zeros straight across. Assuming a simple addition problem, it is "desired to add the following numbers:

next number in the column to be entered is 9 and this is entered by inserting the stylus in the hole in the wheel in gear 56 and rotated from the 9 clockwise to where it stops at the end of the stylus opening 60. The number 9 now appears in the window opening above position F.

Next, the number 3 is entered by inserting the stylus point in the hole opposite the number 3 at position F and since the gear 5-6 has already been rotated to the position with the "9 showing in the window any further rotation beyond the number 1 (in this case 3) causes the carry-over arm- '74 to ride up over the cam 44 and to engage the gear 56 in position E moving it one increment thereby causing .the "1 in the window under E to change to a 2 and at the same time the stylus is carried to the end of track 60 in position F causing the digit 2 to appear under window -F for a total of 22 which is the correct sum of 10 +9+3.

Once moved, the gears 56 and gears 5i remain in position (gear '56 held by spring 66) until manually operated again, thereby accumulating each time and carrying-over as the gear 50 reaches its maximum each time. Carryover arms 44 act only long enough to move the next gear 56 one digit.

While I have shown and described a particular embodiment of my invention together with suggested materials and manufacturing procedure relative thereto, this is by way of illustration only and does not constitute any sort of limitation on the scope of my invention as various alterations, substitutions, changes, deviations, eliminations and variations may be made in the embodiment shown and described without departing from the scope of my invention as shown in the appended claims.

I claim: I

1. In a stylus-operated portable calculator of the type described, 7

(a) a calculator base adapted to be formed in a threedimensional shape from plastic or the like, with a flat upper surface, 7

(1)) circular indentations formed across the upper surface of said'base having the centers thereof in a straight line and each intersecting the next successive indentation,

(c) a second group of circular indentations formed beneath said first group of indentations and having the centers thereof in a stright line with the second indentations each intersecting two of the first indentations located thereabove,

(d) center post formed at each of said first and second indentations,

(e) a spring slot formed across the bottom of said base below said second group of indentations,

(1) each of said first group of indentations having an answer gear positioned therein,

(g) each of said second group of indentations having a stylus-operated input gear located thereon,

' (h) each of said stylus-operated input gears being of substantially solid disc-like construction having a plurality ofteeth formed on the underside thereof and being identified with the indicia of the digits 0 through 9 adjacent a respective gear tooth on the calculator,

( i) each of said stylus-operated gears having a stylus opening formed adjacent a respective gear tooth and each of said stylus-operated gears intersecting with a respective answer gear located thereabove whereby movement of said stylus-operated gear operates a respective answer gear in mesh therewith,

(j) a ratchet spring mounted in said spring slot and there being a plurality of springs each having a bent portion engaging between respective gear teeth on said stylus-operated gears whereby said ratchet spring bends and snaps from one gear position to the next as said stylus-operated gears are moved,

(-k) each of said answer gears having indicated thereon the numbers 0 through 9 corresponding with respective numbers on said stylus-operated gears,

(I) each of said answer gears having a carry-over arm protruding therefrom for the purpose of advancing the next successive answering gear when said gear passes the number 9,

(m) and each of said first group of indentations having a cam therein adapted to raise said carry-over arm on said answer gear to bring same into engagement with said next successive answer gear at the proper time when said answer gear is about to pass the number 9 so as to advance said next successive gear one digit,

(n) and a thin cover member adapted to cover said base and said answer gears and said stylus-operated gears,

(0) said cover having respective stylus-tracks formed therein in alignment with and corresponding to the stylus openings formed in each of said stylus-operated gears whereby a stylus may be inserted through said cover and into a respective stylus hole in said gear.

2. In a manually operated, stylus-operated portable calculator of the type described,

(a) a calculator base adapted to be formed in a rectangular shape from plastic or the like,

(12) a plurality of answer gears on said base having the centers thereof in a straight line and each being adjacent next successive answer gear,

(c) a second group of stylus-operated input gears beneath said first group of gears and having the centers thereof in a straight line with the second gears each meshing with one of the first gears located thereabove,

(d) each of said stylus-operated input gears being of substantially solid disc-like construction having a plurality of teeth formed on the underside thereof and being identified with the indicia of the digits 0 through 9 adjacent a respective gear tooth on the calculator,

(e) each of said stylus-operated gears having a stylus opening formed adjacent a respective gear tooth and each of said stylus-operated gears interacting with a respective answer gear located thereabove whereby movement of said stylus-operated gear operates a respective answer gear in mesh therewith,

(f) a spring means mounted on said base and there being a spring for each gear having a portion engaging between respective gear teeth on said stylus-operated gears whereby said spring bends from one gear position to the next as said stylus-operated gears are moved,

(g) each of said answer gears having indicated thereon the numbers 0 through 9 corresponding with respective numbers on said stylus-operated gears,

(h) and each of said answer gears having a carry-over arm protruding therefrom for the purpose of advancing the next successive answering gear when said gear passes the number 9,

(i and each of said first group of indentations having a cam therein adapted to raise said carry-over arm on said answer gear to bring same into engagement with said next successive stylus-operated input gear at the proper time when said answer gear is about to pass the number 9 so as to advance said next successive gear one digit,

(i) and a thin cover member adapted to cover said base and said answer gears and said stylus-operated gears,

(k) said cover having respective stylus-tracks formed therein in alignment with and corresponding to the stylus openings formed in each of said stylus-operated gears whereby a stylus may be inserted through said cover and into a respective stylus hole in said gear.

3. In a manually operated, stylus-operated portable calculator of the type described,

(a) a calculator base adapted to be formed in a rec tangular shape from plastic or the like,

(17) circular indentations formed across said base having the centers thereof in a straight line and each intersecting the next successive indentation,

(c) a second group of circular indentations formed beneath said first group of indentations and having the centers thereof in a straight line with the second indentations each intersecting two of the first indentations located thereabove,

(:1) each of said first group of indentations having an answer gear positioned therein,

(e) each of said second group of indentations having a stylus-operated input gear located thereon,

(f) each of said stylus-operated input gears being of substantially solid disc-like construction having a plurality of teeth formed on the underside thereof and being identified with the indicia of the digits 0 through 9 adjacent a respective gear tooth on the calculator,

(g) each of said stylus-operated gears having a stylus opening formed adjacent a respective gear tooth and each of said stylus-operated gears interacting with a respective answer gear located thereabove whereby movement of said stylus-operated gear operates a respective answer gear in mesh therewith,

(h) a spring mounted on said base and there being a plurality of springs, portions engaging between respective gear teeth on said stylus-operated gears whereby said spring bends and snaps from one gear position to the next as said stylus-operated gears are moved,

(i) each of said answer gears having indicated thereon the numbers 0 through 9 corresponding with respective numbers on said stylus-operated gears,

(j) and each of said answer gears having a carry-over arm protruding therefrom normally below its respective input gear for the purpose of contacting the next input gear and advancing the next successive answering gear when said gear passes the number 9,

(k) and each of said first group of indentations having a cam therein adapted to raise said carry-over arm on said answer gear to bring same into alignment and engagement with said next successive input gear at the proper time when said answer gear is about to pass the number 9 so as to advance said next successive gear one digit,

(1) and a thin cover member adapted to cover said base and said answer gears and said stylus-operated gears,

(in) said cover having respective stylus openings formed therein in alignment with and corresponding to the stylus openings formed in each of said stylusoperated gears whereby a stylus may be inserted through said cover and into a respective stylus hole in said gear.

4. In a manually operated, stylus-operated portable calculator of the type described,

(a) a calculator base adapted to be formed in a rectangular shape from plastic or the like,

(b) a first group of answer gears positioned on said base,

() a second group of stylus-operated input gears located on said base,

(d) each of said stylus-operated input gears being of substantially solid disc-like construction having a plurality of teeth formed on the underside thereof and being identified with the indicia of the digits 0 through 9 adjacent a respective gear, tooth on the calculator, 10

(e) each of said stylus-operated gears having a stylus opening formed adjacent a respective gear tooth and each of said stylus-operated gears interacting with a respective answer gear located thereabove whereby movement of said stylus-operated gear operates a respective answer gear in mesh therewith,

(f) a ratchet spring mounted in a spring'slot on the (g) each of said answer gears having indicated thereon the numbers 0 through 9 corresponding with respective numbers identifying the respective teeth on said stylus-operated gears and also corresponding with a respective gear tooth on said answer gear and,

(h) each of said answer gears having a carry-over arm 8 i protruding therefrom for the purpose of advancing the next successive answering gear when said gear passes the number 9,

(i) and each of said first group of indentations having a cam therein adapted to raise said carry-over arm on said answer gear to bring same into engagement with said next successive stylus gear to operate said answer gear at the proper time when said answer gear is about to pass the number 9 so as to advance said next successive gear one digit,

(j) and a thin cover member adapted to cover said base and said answer gears and said stylus-operated gears,

(k) said cover having respective stylus-tracks formed therein in alignment with and corresponding to the stylus openings formed in each of said stylus-operated gears whereby a stylus may be inserted through said cover and into a respective stylus hole in said gear.

References Cited in the file of this patent UNITED STATES PATENTS 2,533,443 Farbman Dec. 12, 1950 2,594,566 Kesling Apr. 29, 1952 2,797,047 Lehre June 25, 1957 FOREIGN PATENTS 498,698 Great Britain Ian. 12, 1939 

1. IN A STYLUS-OPERATED PORTABLE CALCULATOR OF THE TYPE DESCRIBED, (A) A CALCULATOR BASE ADAPTED TO BE FORMED IN A THREEDIMENSIONAL SHAPE FROM PLASTIC OR THE LIKE, WITH A FLAT UPPER SURFACE, (B) CIRCULAR INDENTATIONS FORMED ACROSS THE UPPER SURFACE OF SAID BASE HAVING THE CENTERS THEREOF IN A STRAIGHT LINE AND EACH INTERSECTING THE NEXT SUCCESSIVE INDENTATION, (C) A SECOND GROUP OF CIRCULAR INDENTATIONS FORMED BENEATH SAID FIRST GROUP OF INDENTATIONS AND HAVING THE CENTERS THEREOF IN A STRAIGHT LINE WITH THE SECOND INDENTATIONS EACH INTERSECTING TWO OF THE FIRST INDENTATIONS LOCATED THEREABOVE, (D) CENTER POST FORMED AT EACH OF SAID FIRST AND SECOND INDENTATIONS, (E) A SPRING SLOT FORMED ACROSS THE BOTTOM OF SAID BASE BELOW SAID SECOND GROUP OF INDENTATIONS, (F) EACH OF SAID FIRST GROUP OF INDENTATIONS HAVING AN ANSWER GEAR POSITIONED THEREIN, (G) EACH OF SAID SECOND GROUP OF INDENTATIONS HAVING A STYLUS-OPERATED INPUT GEAR LOCATED THEREON, (H) EACH OF SAID STYLUS-OPERATED INPUT GEARS BEING OF SUBSTANTIALLY SOLID DISC-LIKE CONSTRUCTION HAVING A PLURALITY OF TEETH FORMED ON THE UNDERSIDE THEREOF AND BEING IDENTIFIED WITH THE INDICIA OF THE DIGITS "O" THROUGH "9" ADJACENT A RESPECTIVE GEAR TOOTH ON THE CALCULATOR, (I) EACH OF SAID STYLUS-OPERATED GEARS HAVING A STYLUS OPENING FORMED ADJACENT A RESPECTIVE GEAR TOOTH AND EACH OF SAID STYLUS-OPERATED GEARS INTERSECTING WITH A RESPECTIVE ANSWER GEAR LOCATED THEREABOVE WHEREBY MOVEMENT OF SAID STYLUS-OPERATED GEAR OPERATES A RESPECTIVE ANSWER GEAR IN MESH THEREWITH, (J) A RATCHET SPRING MOUNTED IN SAID SPRING SLOT AND THERE BEING A PLURALITY OF SPRINGS EACH HAVING A BENT PORTION ENGAGING BETWEEN RESPECTIVE GEAR TEETH ON SAID STYLUS-OPERATED GEARS WHEREBY SAID RATCHET SPRING BENDS AND SNAPS FROM ONE GEAR POSITION TO THE NEXT AS SAID STYLUS-OPERATED GEARS ARE MOVED, (K) EACH OF SAID ANSWER GEARS HAVING INDICATED THEREON THE NUMBERS "0" THROUGH "9" CORRESPONDING WITH RESPECTIVE NUMBERS ON SAID STYLUS-OPERATED GEARS, (L) EACH OF SAID ANSWER GEARS HAVING A CARRY-OVER ARM PROTRUDING THEREFROM FOR THE PURPOSE OF ADVANCING THE NEXT SUCCESSIVE ANSWERING GEAR WHEN SAID GEAR PASSES THE NUMBER "9", (M) AND EACH OF SAID FIRST GROUP OF INDENTATIONS HAVING A CAM THEREIN ADAPTED TO RAISE SAID CARRY-OVER ARM ON SAID ANSWER GEAR TO BRING SAME INTO ENGAGEMENT WITH SAID NEXT SUCCESSIVE ANSWER GEAR AT THE PROPER TIME WHEN SAID ANSWER GEAR IS ABOUT TO PASS THE NUMBER "9" SO AS TO ADVANCE SAID NEXT SUCCESSIVE GEAR ONE DIGIT, (N) AND A THIN COVER MEMBER ADAPTED TO COVER SAID BASE AND SAID ANSWER GEARS AND SAID STYLUS-OPERATED GEARS, (O) SAID COVER HAVING RESPECTIVE STYLUS-TRACKS FORMED THEREIN IN ALIGNMENT WITH AND CORRESPONDING TO THE STYLUS OPENINGS FORMED IN EACH OF SAID STYLUS-OPERATED GEARS WHEREBY A STYLUS MAY BE INSERTED THROUGH SAID COVER AND INTO A RESPECTIVE STYLUS HOLE IN SAID GEAR. 